The Goldstone SSR did some bistatic Doppler radar imaging of 2024 MK using DSS-14 (transmit) and DSS-13 (receive) at around 2m resolution. The images show that the asteroid is around 150m across:
https://echo.jpl.nasa.gov/asteroids/june2024.goldstone.planning.html
Petr Pravec had already determined that it was a non-principle axis (aka tumbling) rotator from optical observations showing multiple rotation periods from just over an hour down to around 20 minutes.